The Effects of Circumferential Wrist Pressure on Reproduction Accuracy of Wrist Placement in Healthy Young and Elderly Adults

Background. The purposeof this study was to determinethe effect of circumferential wrist pressure on reproductionaccu­ racy of wrist placementin healthy young and elderly adults.A conveniencesample of 20 young adults having a mean age of 22.9 years and 20 elderlyadultswith a mean age of 68.2 years participatedin the study. Method. Blindfolded subjectswere asked to actively self-selecta neutral wrist position (reference) and then, when signaled, to activelyreproducethe previouslyselectedposition.Wristjoint reproductionaccuracywas assessedunder four pressurecon­ ditions: no contact, wrist contact, 10 mm Hg, and 20 mm Hg. A single axis dynamic wrist electrogoniometermeasured three dependentvariables: absolute,constant,and variableerrors.Data were analyzed by meansof multivariate analysis of variance (MANOVA) for repeatedmeasures. Results. No significant differencesin reproductionaccuracy under the four pressureconditionsfor young or elderly adults were found. Conclusions. Healthy young and elderly adults may utilize existing intrinsic feedback and central control mechanismsto achieve accuracy during a reproduction task. Some subjects in both age groups who entered into the study with high error scoresbenefitedfrom circumferential pressureby possiblyrelyingon peripheral mechanisms. Further studiesare neededto de­ tennine the effectof circumferential pressureon subjects withpoor reproductionperformance.